Tank spreader

ABSTRACT

A liquid manure spreading apparatus having a tank and a pump selectively operable to evacuate air from within the tank or supply air to the tank. A safety shut off valve located in the tank having a ball and an elongated float confined in a cage is operable to block the evacuation of air from the tank when the tank is full of liquid manure. A control valve mounted on the pump has a single spool selectively moveable with a handle to an air evacuating position and an air supplying position. A single air line is connected to the valve and tank.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 500,133, filedAug. 23, 1974, now U.S. Pat. No. 4,061,273.

BACKGROUND OF INVENTION

Liquid manure spreading machines have been developed to spread animalmanures on the soil. These machines have a tank mounted on a trailertowed by a vehicle, as a tractor. A pump operated by the tractorfunctions to selectively apply air pressure or withdraw air from thetank. The tank is filled by suction forces applied to a fill hoseconnected to the tank. The material is spread by applying air underpressure to the tank. An example of this type of machine is shown inU.S. Pat. No. 3,523,612. The pump in some air pressure tank spreaders isconnected to the tank with an air pressure line and a separate vacuumline. The pump is an air pump which will become inoperable, damaged andin most cases destroyed when liquid foam, or manures enter the pump.Safety shut off valves are used to protect against liquids, manures andfoam from entering the pump. These valves have been ineffective ineliminating the entry of these materials into the pumps. The result isthat the pumps become inoperative and must be repaired or replaced.

SUMMARY OF INVENTION

The invention is related to a material handling apparatus operable tocollect, transport, and spread liquid and semi-liquid materials onto adesired location. More particularly, the invention is a liquid manurespreader having a tank for storing liquid manure. A tank is supported onmeans connectable to a tractor for moving the tank along the ground.Pump means operates to selectively evacuate air from the tank and supplyair under pressure to the tank. Control valve means connected to an airline and pump means is operable to direct air under pressure into thetank and to vent exhaust air withdrawn from the tank by the pump means.A manure discharge assembly on the tank spreads the manure in a swathbehind the tank when air under pressure is supplied to the tank. Aseparate manure inlet allows manure to move into the tank when air isevacuated from the tank. Safety shut off valve means located inside thetank operates to prevent the evacuation of air from the tank in responseto the full level of liquid manure in the tank. The safety shut offvalve means includes a valving member and an elongated float for movingthe valving member to a closed position to prevent liquids, foams andmanure from entering the pump means. A rigid open cage means confinesthe valving member and the float so that they are free to move inresponse to the level of the liquid manure in the tank. The controlvalve means has a single valving spool operable to selectively connectthe pump means to evacuate air from the tank or supply air underpressure to the tank. A single hose or air line connects the controlvalve means with the tank.

An object of the invention is to provide a liquid material spreadingapparatus with safety shut-off valve structure operable in response tothe level of liquid in the tank of the apparatus to prevent the movementof liquid or foam from the tank into the air evacuating pump. Anotherobject of the invention in to provide control valve means for couplingan air pump to a liquid carrying tank which uses a single line betweenthe valve and tank to selectively carry air from the tank and supply airto the tank. A further object of the invention is to provide a liquidmaterial spreading apparatus with a fill port usable with a fill hosethat is separate from the material discharge assembly of the apparatus.These and other objects of the invention are set forth in the followingdescription of the invention.

IN THE DRAWINGS

FIG. 1 is a top plan view of the vacuum tank material spreader of theinvention connected to a towing vehicle;

FIG. 2 is an enlarged sectional view taken along the line 2--2 of FIG.1;

FIG. 3 is an enlarged sectional view taken along the line 3--3 of FIG.1;

FIG. 4 is an enlarged sectional view taken along the line 4--4 of FIG.2;

FIG. 5 is an enlarged sectional view taken along the line 5--5 of FIG.4;

FIG. 6 is a front elevational view, partly sectioned, of the controlvalve mounted on the pump as shown in FIG. 2;

FIG. 7 is a sectional view taken along the line 7--7 of FIG. 6;

FIG. 8 is a top plan view of the valve FIG. 6, partly sectioned, showingthe valve spool in the vacuum position; and

FIG. 9 is a top plan view of the valve similar to FIG. 8 showing thevalve spool in the pressure position.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIG. 1 there is shown the material spreader of theinvention indicated generally at 10 towed by a power unit 1 such as anagricultural tractor. Spreader 10 has a material discharge assembly 12operable to direct material rearwardly of the spreader 10 in a swathhaving generally even spread pattern 13. The material dispensed from thedischarge assembly 12 has a low profile and a uniform and controlledcenter spread pattern. This spread pattern does not produce roostertailing and result in blow back on the operator. The material dischargeassembly 12 is constructed according to the material spreader structuredisclosed in U.S. Pat. No. 3,980,236. The spreader structure in U.S.Pat. No. 3,980,236 is incorporated in this application by reference. Thespreader 10 is used as part of a liquid manure handling system by hog orpoultry producers and dairymen. Vacuum forces are used to draw themanure into the tank which can have a 1000 to 2000 or more galloncapacity. The manure in the tank is subjected to air under pressure toremove and spread the material. The following description is directed tohandling of liquid manure with spreader 10. It is understood that othermaterials, liquids and semi-solids, can be handled with spreader 10.

Material spreader 10 has an elongated tank 14 mounted on a rectangularframe 16. Two pairs of tandem wheels 17 are connected to frame 16 withan undercarriage having walking beam suspension 16A. Frame 16 has aforwardly converging A frame tongue 18 that is connected to the drawbarof the tractor 11. Mounted on the tongue 18 is a vacuum/pressure pump 19selectively operable to withdraw or evacuate air from the tank 14 ordischarge air under pressure into the tank 14. The pump 19 is connectedto the tractor 11 with a conventional PTO drive 20. Pump 19 is an airpump having a housing carrying a rotor having radial vanes. Other typesof air pumps can be used to evacuate and supply air to the tank 14.

Tank 14 has a circular front wall 21 and circular rear wall 22. A smallwindow 23 is mounted in the upper portion of the front wall 22 toprovide for the visual inspection into the tank. Window 23 is used as avisual indicator for monitoring the level of the material, such asliquid manure in the tank 14. An intake port 15 is mounted on the rearwall 22 above the discharge assembly 12. An inlet or fill hose (notshown) is adapted to be connected to port 15 whereby liquid manure issucked into the tank via the inlet hose. The separate intake port 15 anddischarge assembly 12 provide for clean and easy hookup of the fillhose. As shown in FIGS. 1 and 2, an upwardly directed dome indicatedgenerally at 24 is secured to the top of the front portion of the tank14. Dome 24 comprises upright cylindrical wall 26 having a passage 27leading to the interior of tank 14. An inverted dish shaped cover orhatch indicated generally at 28 closes the top of dome 24. As shown inFIGS. 3 and 4, cover 28 has a downwardly directed circular flange 29. Anannular ring 31 is secured to the inside of flange 29. The end of flange29 and the bottom side of ring 31 are located over an inwardly directedshoulder 32 secured to the inside of the wall 26. shoulder 32 is a ringmember forming a seat for the cover 28. An annular washer or gasket 30is located between the ring 31 and the shoulder 32 to seal the cover 28on the dome 24.

A plurality of clamp assemblies indicated generally at 33 are used tohold the cover 28 in sealing relationship with the dome 24. The clampassemblies 33 are identical in structure. The following description islimited to the clamp assembly 33 as specifically shown in FIG. 3. Clampassembly 33 has a pair of outwardly directed tabs 34 secured to theoutside of wall 26. An eye bolt 36 has a head end located between thetabs 34. A pin 37 extended through the eye of the eye bolt 36 pivotallyconnects the eye bolt to the tabs 34. A pair of radially outwardlydirected ears 38 are secured to an outer peripheral portion of the cover28. The body of the eye bolt 36 is located between the ears 38. A nut 39threaded in the end of the eye bolt engages the top of the ears 38 tohold the cover 28 in a clamped and sealing relation with the dome 24. Anoutwardly directed handle 41 is secured to the nut 39 to facilitate therotation of the nut without the use of special tools.

Cover 28 is connected to the pump with a single line or hose whereby aircan be selectively introduced or withdrawn from the tank. As shown inFIGS. 2 and 4, a tubular member 42 is secured to the center portion ofcover 28. The passage of the tubular member 42 is open to the interiorof the tank. A hose 43 coupled to the tubular member 42 leads to acontrol valve indicated generally at 44 mounted on top of thevacuum/pressure pump 19. Control valve 44 has a single valving member orspool which is operable to selectively connect the pump to the tank tosupply air under pressure to the tank or withdraw air from the tank.

Tubular member 42 has a downwardly directed projection 46 having anoutlet 47 open to the interior of the dome 24. A valve means is operableto close the outlet 47 in response to the level of the liquid materialin the tank 14. The valve means comprises a hollow ball 48 located abovea cylindrical float 49. The ball 48 and the float 49 are located in anopen cage indicated generally at 51. The ball 48 and float 49 are freeto move in a vertical direction toward and away from the projection 46.Cage 51 has a plurality of laterally spaced straps 52 secured to abottom member 54. Member 54 is a flat plate having a large center hole.The upper ends of the straps 52 have outwardly directed tabs 53. Thecage 51 is a generally elongated rectangular unit having an internaldimension larger than the diameters of the ball 48 and float 49 so thatboth the ball and the float have limited lateral movement as well asfree up and down movement.

Cage 51 is attached to the cover 28 to position the ball 48 in verticalalignment with the end of projection 46. Tabs 53 are aligned with legs56 secured to the bottom of cover 28. Legs 56 have outwardly directedportions accommodating nut and bolt assemblies 57 to connect the cage 51to the cover 28.

The ball 48 is a hollow member of flexible rubber or plastic. Thecylindrical float 49 is a foam material, such as polystyrene orpolyurethane. The foam material does not absorb liquids and issubstantially lighter than water so that it will readily float in theliquid material and any foam generated by the liquid material. Theliquid material shown at 58 in FIG. 4 can be liquid manure with theaccompanying bedding. Animal manure, as hog manure, and cattle manureare conventionally transported and spread with this type of materialspreader. The float 49 is carried upward by the liquid material and foamgenerated by agitation of the liquid material. This moves the ball 48 isa closed relationship with the end of projection 46 to prevent liquidand foam from being drawn into the pump 19.

The control valve 44 mounted on the vacuum/pressure pump 19 is shown inFIGS. 6 to 9. Valve 44 has a housing 61. Housing 61 has a generally flatbase 62 which fits on top of the pump 19. The base 62 has ports 63 and64 aligned with the intake and exhaust ports of the pump 19. The centerportion of the top of housing 61 has an upwardly directed nipple 66.Hose 43 is mounted on the nipple to connect the valve 44 in fluidcommunication with the interior of tank 14.

Housing 61 has a transverse bore 67 accommodating a cylindrical spoolindicated generally at 68. A radially outwardly directed handle 69 issecured to one end of the spool 68 to facilitate the rotation of thespool in the bore 67 to selectively connect the pump 19 to evacuate airfrom the tank or supply air to the tank. A pair of side ports 71 and 72in opposite sides of housing 61 are open to separate parts of the bore67. Spool 68 has a first cavity 73 adjacent the handle end of the spoolfor selectively providing a passage between the port 64 and the nipple66 and port 64 and the side port 72. A second cavity 74 in spool 68 isoperable to selectively connect the port 63 with the nipple 66 and theside port 71. As shown in FIG. 7 the cavities 73 and 74 are in rightangle relationship relative to each other.

FIGS. 6, 7, and 8 show the control valve 44 in the pressure position.The spool 68 has been rotated with the handle 69 in a counter-clockwisedirection. The cavity 73 provides a passage between the port 64 and thenipple 66. This permits the air to flow through hose 43 into the tank14. The air is drawn into the pump 19 via the side port 71, cavity 74,and port 63.

FIG. 9 shows the control valve 44 in the vacuum position. The spool 68has been rotated in a clockwise direction with the handle 69. The cavity74 provides for communication between the port 63 and the nipple 66. Theair is exhausted from the pump through the port 64, cavity 73, and sideport 72.

The control valve 44 is mounted on the pump 19 so that the handle 69 canbe conveniently used to switch the spool from a vacuum position to apressure position. The valve 44 is operable to activate air from thetank 14 or supply air to the tank 14 through a single line or hose 43connected to the dome 28.

In use, the spreader 10 is connected to the tractor 11. the tractorpower take off is connected with the PTO drive 21 to operate thevacuum/pressure pump 19. The tank 14 is filled with liquid manure byevacuating air from the tank. The fill hose is connected to the inletport 15 on the back wall of the tank. Suction forces move the liquidmanure through the fill hose and into the tank. The level of the manurein the tank can be visually inspected through the window 23. Theagitation of some types of manure will produce foam on top of the liquidmanure. When the level of the manure in the tank is at the window 23 theoperator turns off the power to the pump 19 and closes the intake valve(not shown) located in the intake port 15. The lever 69 of the controlvalve is moved to the pressure position so that the pump 19 is ready tosupply air under pressure to the tank.

The efficiency and life of the pump 19 is increased if the foam andliquid are not allowed to move to the pump. The safety shut off valvemeans comprising the ball 48 and the float 49 functions to close theinlet to the tubular member 42 when the level of the liquid is adjacentto the window 23 as shown in FIG. 4. The cylindrical float 49 extendedin the generally upright direction moves the ball 48 in an upwarddirection till the opening 47 is closed. The foam and liquid will carrythe cylindrical member 49 in an upward direction thereby preventingfoam, liquids and manures from entering the pump. If foreign materialsenter the pump the vane and rotor structures become inoperative anddestroyed. These structures will break thereby requiring extensiverepair to or replacement of the pump.

The tank is then moved to the field or location where the manure is tobe deposited. The control valve 44 is then moved to the pressureposition by moving the handle 69 toward the tractor. The pump 19operates to supply air under pressure to the tank. The control valve forthe discharge assembly 12 is opened. The material is dispensed in a lowprofile and uniform spread pattern 13 as shown in FIG. 1. The liquidmanure will continually dispense from the tank 14 as long as air underpressure is supplied to the tank. While the tank 14 is empty, thecontrol valve 44 is moved back to its neutral position.

While there has been shown and described preferred embodiments of theinvention, it is understood that changes in structures, materials,arrangement of the structures, and parts may be made by those skilled inthe art without departing from the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A liquid manure spreadercomprising: a tank having a chamber for storing liquid manure, said tankhaving a top portion with a passage open to the chamber, a cover mountedon the tank for closing said passage, means to support the tank formovement along the ground, pump means for selectively evacuating airfrom the chamber and supplying air under pressure to the chamber,control valve means having a single spool to selectively control themovement of air to and from the tank, a single air line means connectingthe valve means with the cover, manure discharge means on the tank forspreading manure when air under pressure is supplied to the tank, manureinlet means allowing manure to move into the tank when air is evacuatedfrom the tank, safety shut-off valve means located inside the tankoperable to prevent the evacuation of air from the tank through the airline means in response to the level of the manure in the tank, saidshut-off valve means including a valving member, an elongated float formoving the valving member to a closed position in response to the levelof the manure in the tank to prevent escape of liquid manure into theline means and pump means, said air line means including a tubularmember mounted on the cover, said tubular member having a projectionextended below the cover and engageable with said valving member toclose the air line means, open cage means secured to said cover andextended downwardly into the tank chamber to confine the valving memberand float, said cage means having a plurality of rigid members spacedfrom each other and surrounding the valving member and float, saidspaced members providing elongated openings between the chamber andfloat whereby the float responds to the level of liquid in the tankchamber to close the air line means, and means attaching the rigidmembers to the inside of the cover, said means attaching the spacedmembers to the inside of the cover comprise legs secured to the coverand releasable fastening means connecting the spaced members to the legswhereby the spaced members, valving member and float can be removed fromthe cover.
 2. The spreader of claim 1 wherein: the valving member is aball and the float is an elongated cylindrical member.
 3. The spreaderof claim 2 wherein: the cylindrical member is an expanded foam plasticmember.
 4. The spreader of claim 1 wherein: the tank has an upright domesecured to the top portion of the tank, said dome surrounding saidpassage open to the chamber, said cover means being mounted on the domefor closing the passage.
 5. The spreader of claim 1 wherein: said meansattaching the rigid members to the inside of the cover comprise legssecured to the cover and fastening means connecting the legs to therigid members of the cage means.
 6. The spreader of claim 1 wherein: themanure inlet means is separated from the manure discharge means.
 7. Asafety shut-off valve means for use with a tank having a chamber forcarrying a liquid, said tank having a top portion with a passage open tothe chamber, a cover mounted on the tank for closing said passage, meansfor evacuating air from the chamber, and line means connecting the meansfor evacuating air from the chamber with the cover comprising: a valvingmember movable to a closed position to close the line means to stopevacuation of air from the chamber and prevent escape of liquid to themeans for evacuating air from the chamber, a float movable with thelevel of the liquid in the chamber to move the valving member to theclosed position, rigid open cage means attachable to said cover andextended downwardly into the chamber to align and confine the valvingmember and float, said cage means having a plurality of spaced rigidmembers surrounding the valving member and float, said spaced membersproviding elongated openings between the chamber and float whereby thefloat responds to the level of liquid in the tank chamber to close theair line and means attaching the members to the inside of the cover,said attaching the spaced members to the inside of the cover compriselegs secured to the cover and releasable fastening means connecting thespaced members to the legs whereby the spaced members, valving memberand float can be removed from the cover.
 8. The shut-off valve means ofclaim 7 wherein: the valving member is a ball and the float is anelongated cylindrical member.
 9. The shut-off valve means of claim 8wherein: the cylindrical member is an expanded foam plastic member. 10.The shut-off valve means of claim 7 for use with a tank having anupright dome surrounding the passage open to the chamber, said coverbeing mounted on the dome for closing the passage, wherein: the linemeans has a tubular projection secured to the cover and extended intothe chamber, said cage means confining the valving member and floatbeing secured to the cover whereby the valving member is engageable withthe tubular projection to close the line means.
 11. The shut-off valvemeans of claim 10 wherein: the valving member is a ball engageable withthe tubular projection to close the line means, and said float is anelongated cyclindrical member engageable with a ball.
 12. A cover andshut-off valve means for use with a tank having a chamber for holding aliquid and a top portion having a passage open to said chamber, meansfor evacuating air from the chamber, and air line means connecting thecover to the means for evacuating air from the chamber comprising: acover mountable on the tank for closing the passage, means on the coverconnectable to the line means to allow air to be evacuated from thechamber, a valving member movable to a closed position to close the linemeans to stop evacuation of air from the chamber and prevent escape ofliquid to the means for evacuating air from the chamber, a float movablewith the level of liquid in the chamber to move the valving member tothe closed position, open cage means connected to the cover and adaptedto project into the chamber to align and confine the valving member andfloat, said cage means having a plurality of spaced members surroundingthe valving member and float, said spaced members providing elongatedopenings between the chamber and float whereby the float responds to thelevel of liquid in the tank to close the air line means, and meansattaching the members to the inside of the cover, said means attachingthe spaced members to the inside of the cover comprise legs secured tothe cover and releasable fastening means connecting the spaced membersto the legs whereby the spaced members, valving member and float can beremoved from the cover.
 13. The cover and shut-off valve means of claim12 wherein: the valving member is a ball and the float is an elongatedcylindrical member.
 14. The cover and shut-off valve means of claim 13wherein: the cylindrical member is an expanded foam plastic member. 15.The cover and shut-off valve means of claim 12 wherein: the means on thecover connectable to the air line means includes a tubular projectionmounted on the cover and extended into the chamber, said valving memberbeing engageable with the tubular projection to close the air linemeans.
 16. The cover and shut-off valve means of claim 12 wherein: saidspaced members of the cage means includes a plurality of laterallyspaced straps and angle members surrounding the valving member andfloat.
 17. The cover and shut-off valve means of claim 16 wherein: saidlaterally spaced elongated straps and angle members have a generallyrectangular configuration.
 18. The cover and shut-off valve means ofclaim 12 wherein: said means attaching the members to the inside of thecover comprise legs secured to the cover, and fastening means connectingthe legs to the members of the cage means.
 19. A liquid manure spreadercomprising: a tank having a chamber for storing liquid manure, anupright dome secured to the top of the tank, said dome having an openupper end and a passage open to the chamber, a cover mounted on the domeclosing the open upper end of the dome, a tubular member mounted on thecover having a passage open to the dome passage, means to support thetank for movement along the ground, pump means for selectivelyevacuating air from the tank and supplying air under pressure to thetank, control valve means having a single spool and a handle connectedto the spool to move the spool to selectively control the movement ofair to and from the tank, a single air line means connecting the valvemeans with the tubular member whereby the pump means is in aircommunication with the chamber, manure discharge means on the tank forspreading manure when air under pressure is supplied to the chamber,manure inlet means allowing manure to move into the tank when air isevacuated from the tank, safety shut-off valve means located in the domepassage and chamber operable to prevent the evacuation of air from thetank through the air line means in response to the level of the manurein the tank, said shut-off valve means including a valving member, anelongated float for moving the valving member to a closed position inresponse to the level of the manure in the tank chamber to preventescape of liquid manure into the line means and pump means, and opencage means extended downwardly from the cover into the tank chamber toalign and confine the valving member and float, said cage means having aplurality of members spaced from each other surrounding the valvingmember and float, said spaced members providing elongated openingsbetween the chamber and the float, whereby the float responds to thelevel of liquid in the tank to close the air line means, and meansconnecting the members to the cover, said means attaching the spacedmembers to the inside of the cover comprise legs secured to the coverand releasable fastening means connecting the spaced members to the legswhereby the spaced members, valving member and float can be removed fromthe cover.
 20. The spreader of claim 19 wherein: the valving member is aball and the float is an elongated cylindrical member.
 21. The spreaderof claim 20 wherein: the cylindrical member is an expanded foam plasticmember.
 22. The spreader of claim 19 wherein: the upright dome has aninwardly directed shoulder located below the top edge of the dome, saidcover having a bottom edge engageable with said shoulder, and meansreleasably connecting the cover to the dome.
 23. The spreader of claim19 including: means releasably connecting the cover to the dome.
 24. Thespreader of claim 19 wherein: the tubular member has a tubularprojection extended into the tank chamber, said valving member includinga ball engageable with the tubular projection to close the line means,and said float being an elongated cylindrical member engageable with theball.
 25. An apparatus for storing liquid material comprising: a tankhaving a chamber for carrying a liquid, an upright dome secured to thetop of the tank, said dome having an open upper end and a passage opento the chamber, a cover mounted on the dome closing the open upper endof the dome, means for carrying material to the tank and discharging thematerial into the chamber, a pump for evacuating air from the chamber,line means connecting the pump with the cover whereby on operation ofthe pump air is evacuated from the chamber and material is dischargedinto the chamber, air shut-off valve means mounted on the cover, saidvalve means having a valving member movable to a closed position toclose the line means to stop evacuation of the air from the chamber andprevent escape of liquid to the pump, a float movable with the level ofthe liquid in the chamber to move the valving member to the closedposition, and open cage means attachable to the cover extendeddownwardly into the chamber to confine the valving member and float,said cage means having a plurality of spaced members surrounding thevalving member and float, said spaced members providing elongatedopenings between the chamber and the float, whereby the float respondsto the level of liquid in the tank chamber to close the air line means,and releasable means attaching the spaced members to the cover wherebythe spaced members, valving member and float can be removed from thecover.
 26. The apparatus of claim 25 wherein: the valving member is aball and the float is an elongated cylindrical member.
 27. The apparatusof claim 26 wherein: the cylindrical member is an expanded foam plasticmember.
 28. The apparatus of claim 25 wherein: the line means has atubular projection secured to the cover and extended into the chamber,said cage means confining the valving member and float being secured tothe cover means whereby the valving member is engageable with thetubular projection to close the line means.
 29. The apparatus of claim28 wherein: the valving member is a ball engageable with the tubularprojection to close the line means, and said float is an elongatedcylindrical member engageable with a ball.
 30. A liquid manure spreadercomprising: a tank having a chamber for storing liquid manure, meanshaving an opening in communication with the chamber, a cover closingsaid opening, pump means for selectively evacuating air from the chamberand supplying air under pressure to the chamber, control valve means forselectively controlling the movement of air to and from the chamber, airline means connected to the cover and valve means providing an airconnection between the valve means and the chamber, manure dischargemeans on the tank for spreading manure when air under pressure issupplied to the chamber, manure inlet means allowing manure to move intothe chamber when air is evacuated from the chamber, safety shut-offvalve means located inside the chamber operable to prevent theevacuation of air from the tank through the air line means in responseto the level of the manure in the chamber, said shut-off valve meansincluding valving means movable to a closed position in response to thelevel of the manure in the chamber to prevent escape of liquid manureinto the air line means and pump means, and open cage means attachingthe shut-off valve means to the cover, said open cage means including aplurality of spaced members providing a plurality of openings betweenthe chamber and the valving means of the shut-off valve means, wherebythe shut-off valve means responds to the level of liquid in the tankchamber to move the valving means to its closed position, and releasablemeans attaching the spaced members to the cover whereby the spacedmembers and valving means can be removed from the cover.
 31. Thespreader of claim 30 wherein: the valving means is a ball and anelongated cylindrical float.
 32. The spreader of claim 31 wherein: thecylindrical member is an expanded foam plastic member.
 33. The spreaderof claim 30 wherein: the tank means has an upright dome with an open topsecured to the top of the tank, said cover means being mounted on thedome and closing the open top of the dome, said sut-off valve meansincluding cage means mounted on the cover and confining the valvingmeans.
 34. The spreader of claim 33 wherein: the line means has atubular projection extended into the tank chamber, said valving memberincluding a ball engageable with the tubular projection to close theline means, and said float being an elongated cylindrical memberengageable with the ball.